1. Field of the Invention
The present invention relates to a busbar structure.
2. Description of the Related Art
In an electric storage device having a plurality of single batteries (unit cells), in the plurality of single batteries arranged in a predetermined shape, one side of positive electrodes and the other side of negative electrodes of the adjacent single batteries are electrically connected in series by a connecting conductor such as a busbar (see JP-A-2012-74338, etc.).
The electric storage device having a plurality of single batteries desirably has a fuse function in the connecting conductor to prevent a current exceeding the rating from flowing to a specific single battery. In this case, it is desirable to reduce the thickness in the fuse shape of the busbar as the connecting conductor to satisfy the fusing characteristic. In addition, it is desirable that the busbar (an inter-battery connection portion) has a thick thickness to prevent the temperature rising when a current is applied.
To realize both the fuse function and the inter-battery connection function by the busbar, the fuse portion and the inter-battery connection portion are provided separately with different thickness. In a battery pack in which a large number of single batteries are connected by the busbar, when the fuse portion and the inter-battery connection portion are separate parts, the number of parts is remarkably increased.